Dynamo-electric machine.



J. E. NOEGGERATH. DYNAMC ELECTEIC MACHINE.

APPLICATION FILED JUNI! '1, 1908. 937,462. Patented Oct. 19, 1909.

2 SHEETS-SHEET 1.

ATT f J. E. NOEGGERATH. DYNAMO ELBGTRIG MACHINE.

APPLICATION FILED TUNE 1, 1908.

Patented Oct. 1'9, 1909.

f l INVENTU JAKDE, E. DEGGERA fv v.

MA1-MESSE: I v I R TH UNITED STATESY PATENT OFFICE.

JAKOIB E. NOlii(IjrGrERA'lI-I,v 0F SCHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELEC- TRIO COMPANY, A CORPORATION OF NEW YORK. i

i DYNAMIC-ELECTRIC MACHINE.

Specification of Letters `Patent.

Patented oet. 19, 1909.

Application led June 1, 1908. Serial No. 435,857.

To alt whom it may concern:

Be 1t known that I, J AKOB E. NOEGGERATH,

l a citizen of the .United States, residing at Schenectady, county of Schenectady, State of New York, have invented certain new and useful Improvements in Dynamo-Electric Machines, of which the following is a speci-- fication.

,My invention relates to dynamo-electric machines, and in certain of its aspects relates specifically to unipolar machines, but in other aspects it is limited only to machines having certain characteristics which, while ordinarily found in unipolar machines, are sometimes present in machines of other types.

One feature of my invention relates to the collector-rings of the machine. Vhere large currents are to be collected, as, for instance, in low-voltage unipolar machines, it is ordinarily desirable to employ sets of collector rings, the several rings of each set being in electrical connection-with each other.

One feature of my invention consists in formingv -a set of' collector rings out of a single casting, which is cut in such a manner as to form a plurality of rings separated by air-spaces. The casting is preferably formed withv interior radial webs which serve to unite the collector rings mechanically, and also act as vanes to force air through the spaces between the collector rings when the machine 'is running. lThe armature is so formed as to permit a free flow of. air to the rings.

Another feature of my invention relates to means for balancing end thrusts, due to an unsymmetrical arrangement of the field magnet. In smallsunipolar machines, particularly, it is sometimes ,cheaper to employ an unsymmetrioal arrangement of the field magnet with a single field coil, rather than a symmetrical arrangement which ordinarily requires two field coils. In such a case, an end-pull on the armature is likely to be produced. One feature of my invention consists in providing means for balancing this end-pull consisting of a mass of magnetic material, as, for instance, a steel ring surrounding the end of the armature, and adapted to be attracted in an axial direct-ion by the flux of the field magnet.

Still another feature of my invention consists in means for reducin or removing the stray field from a part o the machine. A

machine having a winding concentric with the shaft is likely to produce a strong stray field at its ends, which may'injuriously affect an engine coupled to the machine or other apparatus close to the machine.

One feature of my invention consists in providing a conductor in circuit with the armature, and so arranged that the armature current iiowing through it produces a magneto-motive force neutralizing the stray fiuX of the field magnet at that point.

My invention will best be understood by reference to the accompanying drawings, in which- Figure 1 shows a side elevation, partly in cross-section, of a unipolar machine arranged in accordance with my invention; Fig. 2 shows a detail of the means for balancing end-pullsgIiigs. 3 and are detail views of one set of collector rings; and Fig. 5 is an end-elevation of the machine.

' Referring first to Fig. l, A represents the armature, and I the field magnet'of a unipolar machine. O represents the field winding, which comprises a single coil concentric with the armature. The fiuX produced by this coil passes into and out of the armature througtrthe two air gaps shown. The armature carries two sets of collector rings, which are formed out of two castings D and D', in electrical contact with the body of the armature. Each casting is out or slotted circumferentially, so as to form a plurality of collector rings d. The uncut portions of the casting form internal radial webs, as is best shown in Fig. 4, which webs serve both to unite the rings d mechanically, and to act as passages a free flow of air to the collector rings is produced by the blower action o f the webs of casting D when the machine 1s in motion.' The other casting D is bolted to the end of the armature 'and forms in effect an overhanging flange. 'It willbe undererated in the body of the armature, itself, between the two sets of collector rings, and

v.stood that the current of the machine is gen-- of the machine, adjacentto the field coil C,

the conductor 'F is led cireumierentially nearly around. the machine, as is shown in V T rf r 1g. a. lhe connections lrom the brushes .to the'conductor P are distributed, these con- -vthe axis of the machine.

produced at the end ot t-he machine by nections being shown at f1, and The connection .te the external eircu' 'l however, is made at f, near one end of the conductor F. The result is that the current flowing from the brushes through conductor F flows in a general circumferential direction, and consequently inducesa magnetic force along rthis .magneto-- motive force opposes and tends to neutralize the stray field which would otherwise be the field Winding` magnet is iro vided with large holes, affording ilree access to the brushes bearing on the casting D.

` It will be seen, from Fig. l, that, the field magnet is not symmetrical -with respect to the armature. With the construction shown, there is a tendency for the rfieldwinding to pull the armature to the lett. To counter- The Field Ibalance this )ull l orovide a rin G of iron i c s or steel, surrounding the end o1 the armature close to the field magnet. rlhe flux passing' from thefield magnet into this ringproduces a vpull on it tending to move the armature to the right. This pull neutralizes the pull on the armature itself. The position of ring G is preferably made adjustable in an axial direction. A convenient arrangement for doing this is indicated in Fig. 2, in which the armature is provided with a plu rality of h'ol s g at varying distances from its end, into which holes the screws or bolts holding ring G may enter.

What I claim as nei' and desire to sec-ure Aby Letters Patent of the United States, is,-

l. In a dynamo-electric machine, a revolvlng armature having collector rlngs, a plurahtyof-sald rings comprising a set formed of a single castingin electrical contact with the body of the armature.

2. In a dynamo-electric machine, in combination with the armature, a casting' in electrical Contact With the armature slotted to forma plurality of collector ringshseparated by air spaces.

3. In a. dynamo-electric machine, in combination with thc armature, a casting carried by the arniature and slotted to torni a plu` rality et collector rings separated .by air spaces, and having internal radial 'webs mechanically unitingv the rings and serving iu operation to torce air through the spaces between the rings.

. et. ln adynamo-electric machine, in coinb-ination with the armature, a casting carried by the armature and slotted to form a plurality of collector rings separated by air spaces, the body of said armature being formed with passages adapted. to permit a free flow of air outwardly through the spaces etu'een said rings.

.ln a dynaino-electric machine, in com` bination with the armature, a casting carried by the armature and slotted to form ay plurality of collector rings separated by air spaces, and having internal radial webs mechanically uniting the .lrings and serving in operation to torce air through the 'spaces bctu'een the rings, the body of said armature being termed with passages adapted to permit a tree flow of air to the spaces between said Webs.

6. ln a dynamo-'electric machine, a revolvirrel armature, a field magnet unsymmetrical with respect to the armature, whereby an end-pull is'produced on the armature, and a mass of magnetic material carried by the armature in position to be attracted' by the field .flux so as to counterbalance the endpull on the armature itself.

7. in a dynamo-electric machine, a revolvinf.; armature, a field magnet unsymmetrical with respect to the armature, whereby an end-pull is produced on the aramture, and mass of magnetic material ycarried by the armature in position to be attracted by the field flux se as to ccmnter-balaiwe the endpull on the armature itself,l said mass being adjustable in position to Vary the attraction thereon of the field flux.

8. ln a dynamo-electric machine, av revolving armature, a iield magnet having a Winding' concentric with the armature and unsymmetrically anged wi h respect thereto, v-:hcreby an end-pull is produced on the armature, and a magnetic ring` surrmiridingthe armature in posit-ion to be attracted axially by the held flux.

9. ln a dynamo-electric machine, a reyolving armature. a field magnet having a winding` concentric with. the armature and unsyunnetrically arranged 'with respect thereto, whereby an end-pull is produced on the armature, and a magnetic ring` surrounding the armature in position to be attracted axially by the field linx, said ring being` axially adjustable in position.

l0. ln a dynamo-electric machine, arevolving armature, a i'ield magnet having a Winding' concentric With the armature, means for collecting the current induced in th'e armature, a stationary conductor located near the end of'the in a circumferential direction nearly around the machine, a connection from a point near one end of said conductor to an external circuit, and a connection from a point near the other end of said conductorato` certainl of said current c- "ecting' means `ilereby the lcurrent collected therebyvjflows through the greater part of said conductor and produces an axial magnetdmotive force 'opposing the stray field of the eld magnet.

1l. In a unipolar dynamo-electric machine, a revolvingarmatur'e, a field magnet having a winding concentric With the armature, means for collecting the curre'ntiinduced in the armature,` a stationary conductor located near the end of the machine and extending 'in a circumferential direction nearly around the machme, 'connections from a plurality of separated points on. said -conductor to said collecting means, and a machine and extending I lectorrings separated by air spaces, the armature being provided With passages adapted to permit the flow of air through the armature body to said rings.

14. In Aa unipolar dynamo-electric machine, a revolving armature having' an'overhanging flange at one end, said flange being slotted to form-a plurality of collector rings separated by air spaces and having interior radial Webs mechanically uniting said rings and acting to force air between the rings in operation.

` 15. In a unipolar dynamo electric machine, a revolving armature, and a casting surrounding the central portion of the armature and slotted to form a plurality of collector rings separated by air spaces, the armature being provided with passages adapted to permit the lloW of air through the armature body to said rings, andl said casting having' interior radial Webs in engagement With the periphery of the arma' ture serving to unite said rings mechanically and to force air between sa1d rlngs in operation.

In Witness whereof', I have hereunto set my hand this 29th day of May 1908.

JAKoB E. NOEGGERATH. Vitnesses BENJAMIN B. HULL, HELEN ORronD. 

